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arXiv · 0711.4671

Duality Symmetry and the Cardy Limit

Suresh Nampuri·Prasanta K. Tripathy·Sandip P. Trivedi
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Abstract

We study supersymmetric and non-supersymmetric extremal black holes obtained in Type IIA string theory compactified on K3 X T^2, with duality group O(6,22,Z) X SL(2,Z). In the Cardy limit an internal circle combines with the AdS_2 component in the near horizon geometry to give a BTZ black hole whose entropy is given by the Cardy formula. We study black holes carrying D0-D4 and D0-D6 brane charges. We find, both in the supersymmetric and non-supersymmetric cases, that a generic set of charges cannot be brought to the Cardy limit using the duality symmetries. In the non-supersymmetric case, unlike the supersymmetric one, we find that when the charges are large, a small fractional change in them always allows the charges to be taken to the Cardy limit. These results could lead to a microscopic determination of the entropy for extremal non-supersymmetric black holes, including rotating cases like the extreme Kerr black hole in four dimensions.

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Suresh Nampuri, Prasanta K. Tripathy, Sandip P. Trivedi. 2008-06-26. Duality Symmetry and the Cardy Limit. https://doi.org/10.1088/1126-6708%2F2008%2F07%2F072

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